1. Field of the Invention
Embodiments relate to radio communications, and more particularly, to a method and apparatus for transmitting and receiving signals based on signal interference.
2. Description of the Related Art
A Nyquist rate is used to transmit signals without inter-symbol interference (ISI). In an orthogonal frequency division multiplexing (OFDM) system, a rate and a shape of a pulse are determined to transmit signals without ISI within an allowed bandwidth, which is referred to as Nyquist pulse generation. The pulse determined by the Nyquist pulse generation may have a maximum transmission rate without ISI within the provided bandwidth.
Meanwhile, faster than Nyquist (FTN) pulse generation is used to increase a transmission rate of the Nyquist pulse generation. FTN transmission inevitably causes ISI in a transmission signal. However, despite the ISI, the FTN transmission increases a predetermined extent of a symbol transmission rate without a loss of bit error rate (BER), when compared to the Nyquist rate.
Further, a direct sequence spread spectrum (DS-SS) and a frequency hopping spread spectrum (FH-SS) are used to secure a high security and efficient use of frequency resources. In the aforementioned frequency spread schemes, users transmit and receive signals by utilizing unique spread codes and frequency hopping patterns. Thus, the frequency spread schemes enable frequency sharing among multiple users and security communications through the unique codes and patterns.